The present invention relates to an ink jet printing apparatus for a data processing system, a facsimile transceiver or the like.
Ink jet printers are becoming increasingly popular due to their high operating speed, print quality, etc. Generally such a printer comprises an ink ejection or ink jet printing head which is moved relative to a sheet of paper. The head is actuated by electrical signals to suitably eject droplets of ink onto the paper to form characters, patterns and the like as desired. The head is moved relative to the paper in an orthogonal scanning pattern which covers the entire surface of the paper.
An ink tank of necessarily small size is attached to the head for supplying ink thereto. A larger ink tank is mounted in a stationary position at an end of a carriage which supports the head for reciprocating movement for periodically supplying ink into the small tank. Sensors are attached to both tanks for indicating when the amount of ink therein is low. When the amount of ink in the small tank attached to the head runs low, the first tank is moved into communicating engagement with the large stationary tank and filled therefrom. When the amount of ink in the large tank runs low, an annunciator such as a buzzer is energized to urge the apparatus operator to fill the large tank.
The prior art apparatus described above is disadvantageous in that two sensors are required, one for the small tank and one for the large tank. This unnecessarily increases the complexity and cost of the apparatus.